[PATCH AUTOSEL 5.1 24/60] bpf, tcp: correctly handle DONT_WAIT flags and timeo == 0
From: Sasha Levin <sashal@kernel.org>
Date: 2019-06-04 23:22:55
Also in:
bpf, lkml, stable
Subsystem:
bpf [l7 framework] (sockmap), networking [general], networking [tcp], the rest · Maintainers:
John Fastabend, Jakub Sitnicki, Jiayuan Chen, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Neal Cardwell, Linus Torvalds
From: John Fastabend <john.fastabend@gmail.com>
[ Upstream commit 5fa2ca7c4a3fc176f31b495e1a704862d8188b53 ]
The tcp_bpf_wait_data() routine needs to check timeo != 0 before
calling sk_wait_event() otherwise we may see unexpected stalls
on receiver.
Arika did all the leg work here I just formatted, posted and ran
a few tests.
Fixes: 604326b41a6fb ("bpf, sockmap: convert to generic sk_msg interface")
Reported-by: Arika Chen <redacted>
Suggested-by: Arika Chen <redacted>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/ipv4/tcp_bpf.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/net/ipv4/tcp_bpf.c b/net/ipv4/tcp_bpf.c
index 4a619c85daed..3d1e15401384 100644
--- a/net/ipv4/tcp_bpf.c
+++ b/net/ipv4/tcp_bpf.c@@ -27,7 +27,10 @@ static int tcp_bpf_wait_data(struct sock *sk, struct sk_psock *psock, int flags, long timeo, int *err) { DEFINE_WAIT_FUNC(wait, woken_wake_function); - int ret; + int ret = 0; + + if (!timeo) + return ret; add_wait_queue(sk_sleep(sk), &wait); sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
--
2.20.1